Mysterious craters in Siberia linked to hidden methane explosions
Since 2014, mysterious craters have started appearing in the northwestern part of Siberia. These new holes in the ground are causing significant concern, and researchers are trying to understand their formation mechanism. An interesting hypothesis has emerged.
Since 2014, mysterious craters have started appearing in northwestern Siberia. According to next.gazeta.pl, the most recent one formed in August of this year. The issue has drawn the attention of scientists who are attempting to explain the mechanism of their formation. One hypothesis linked the craters to natural gas deposits. Another suggested that the craters form after methane explosions triggered by permafrost thawing.
After studying the craters, a team from the University of Cambridge and the University of Granada reached a slightly different conclusion. "Very specific conditions must exist for this phenomenon to occur" — explains Ana Morgado, a chemical engineer from the University of Cambridge and one of the study's authors, as quoted by "Advancing Earth and Space Science". "We are talking about a very niche geological space," she added.
Attempting to solve the mystery, scientists questioned whether chemical or physical processes caused the explosions. As explained by Julyan Cartwright, a geophysicist with the Spanish National Research Council and a participant in the study, there are only "two ways to trigger an explosion". "Either a chemical reaction occurs, resulting in an explosion, like a dynamite blast, or you inflate a bicycle tire until it explodes — that's physics," indicated the scientist.
According to scientists, mere thawing of permafrost is not enough to cause an explosion, although this process is highly significant. Researchers have focused on cryopegs, pockets of cold brines, which might be closely related to the formation of craters in Siberia.
Underneath cryopegs lies a layer of crystallized methane hydrates (methane clathrate, methane hydrate). These are kept stable by the high pressure and low temperatures inside these cold brine pockets. The situation changes when water from thawing permafrost starts seeping into the brines.
This may lead to the formation of craters in Siberia
In short, the entire process resembles a balloon bursting when too much gas fills it. The increasing pressure inside the cryopegs creates fissures in the soil, which travel upwards from the cryopeg towards the surface.
The cracked soil then causes a sudden drop in pressure at depth. This change damages the methane hydrates below the cryopeg, causing methane to revert to a gaseous state, leading to a physical explosion.
According to scientists, this process occurs over decades, which means we don't observe these phenomena very often. Simultaneously, scientists warn that "the amount of methane released may have a significant impact on global warming".
